Bipolar Disorder, Schizophrenia, and Cardiometabolic Comorbidities Lead to Greater Mortality
Schizophrenia and bipolar disorder have approximately twice the rate of diabetes and metabolic syndrome as the general population, and twice the risk for premature mortality.
Patients with schizophrenia and bipolar disorder (BPD) and a high burden of cardiometabolic comorbidities have a higher risk for hospital readmission, longer hospital stay, and increased mortality, according to a new study1 published in the February issue of the Annals of General Psychiatry.
Schizophrenia and BPD have approximately twice the rate of diabetes and metabolic syndrome than in the general population, and twice the risk for premature mortality. This state is complicated by atypical antipsychotic treatment, which increases the risk of developing metabolic syndrome, diabetes, and hyperlipidemia.
Thirty-day hospital readmissions are a "significant predictor of long-term mortality," according to the authors. A 2013 analysis of readmission trends2 found that schizophrenia, mood disorders, and diabetes were among the top 20 conditions with the highest all-cause 30-day readmission rates.
To assess the effect of cardiometabolic comorbidity on length of hospital stay, mortality, and healthcare costs during the initial admission and on the 30-day readmission rate, Christoph Correll, MD, professor, Center for Psychiatric Neuroscience, Feinstein Institute for Medical Research, Manhasset, New York, and colleagues conducted a retrospective database analysis of 57,506 patients with schizophrenia and 124,803 with BPD.
They found that 66.1% of patients with schizophrenia had ≥1 cardiometabolic comorbidity, and 39.3% had ≥2 comorbidities. Of the patients with both schizophrenia and BPD, 60.5% had ≥1 cardiometabolic comorbidity, and 33.4% had 2 or more. Diabetes affected roughly a quarter of patients with both conditions.
The average length of stay for patients with schizophrenia and BPD was 8.5 and 5.2 days, respectively. Although each additional cardiometabolic comorbidity was associated with increased length of stay for patients with BPD (P <.001), this association did not hold for patients with schizophrenia.
During the index hospitalization, the mortality rates were 1.2% and 0.7% for patients with schizophrenia and BPD, respectively. For patients with BPD, each additional cardiometabolic comorbidity was associated with a statistically significant increase in mortality (odds ratio [OR], 1.218; P <.001), whereas patients with schizophrenia had a numerical increase in mortality (OR, 1.014; P =.727).
Incremental cardiometabolic comorbidities in patients with schizophrenia and BPD were associated with a 3.1% and 6.4% increased risk for early readmission, respectively.
"The results of this study highlight the importance of identifying optimal treatment regimens of patients with serious mental illness," the authors write, encouraging adequate monitoring for cardiometabolic complications, considering alternative antipsychotic regimens with lower cardiometabolic risk profile, increased coordination of care, and efforts to improve patients' physical health.
The authors caution that this observational study "precludes any determination of causal relationship between cardiometabolic comorbidities and the outcomes," because the data were drawn from a database consisting of administrative, rather than research, data.
Other factors may also have "confounded the observed relationships," but although further research is needed, the authors state that their findings "further underscore the need for improved detection and management of cardiometabolic risk factors in patients with schizophrenia or [BPD] across different clinical care setting."
1. Correll CU, Ng-Mak DS, Stafkey-Mailey D, Farrelly E, Rajagopalan K, Loebel A. Cardiometabolic comorbidities, readmission, and costs in schizophrenia and bipolar disorder: a real-world analysis [published online February 10, 2017]. Ann Gen Psychiatry. doi: 10.1186/s12991-017-0133-7
2. Fingar K, Washington R. Trends in Hospital Readmissions for Four High-Volume Conditions, 2009-2013. Rockville, MD: Agency for Healthcare Research and Quality; 2015. https://www.hcup-us.ahrq.gov/reports/statbriefs/sb196-Readmissions-Trends-High-Volume-Conditions.jsp. Accessed March 25, 2017.